Integration of voice store and forward facility

ABSTRACT

Call completion apparatus is disclosed for enhancing the integration of voice store and forward facilities with calling parties attempting to complete telephone calls to a telephone switching system. The call completion equipment intercepts incoming calls, provides voice prompts to the calling parties, and collects telephone extension digit information. On a determination of the unavailability of the called party, the call completion equipment prompts the calling party concerning an optional connection to voice store and forward equipment. In response to the input of a digit code by the calling party, the call completion equipment consults personality tables, translation tables and call flow control tables to provide all the appropriate information which is outpulsed through the telephone switching system to the voice store and forward facility. The operations of the call completion equipment in establishing communications with the voice store and forward facility are transparent to the calling party.

RELATED APPLICATION

"Buxy/No-Answer Call Completion Equipment", by Morganstein et. al., Ser.No. 909,755, filed Sept. 22, 1986.

TECHNICAL FIELD OF THE INVENTION

The present invention relates in general to telecommunicationsequipment, and more particularly relates to methods and apparatus forinterfacing voice store and forward facilities into a telephoneswitching system.

BACKGROUND OF THE INVENTION

The telecommunication field continues to experience an expansion of newfunctions and features to further enhance voice communications. Onefeature which has gained wide acceptance is a voice store and forwardfeature which allows storage and retrieval of voice messages betweenindividuals without the need of the individuals to communicate directlywith each other. The voice store and forward feature is generally acentrally located system having a number of "voice mailboxes" which canbe reached by persons desiring to leave a message for another person,and where the other person can call in at a later time and retrieve suchmessage. With this arrangement, persons can communicate in an indirectmanner, notwithstanding their general unavailability for directcommunications.

Voice store and forward facilities are adapted for use with telephoneswitching systems so that subscribers can communicate indirectly withother subscribers having assigned voice mailboxes. The deposit of avoice message by an outside party calling into a telephone switchingsystem is not always so easily accommodated. Indeed, a personuninitiated with the procedures for invoking the services of voice storeand forward facilities often finds it cumbersome to utilize suchfeatures. The voice store and forward feature is generally invokedthrough a telephone switching system when the called party's telephoneset is busy, or when there is no answer to the incoming call.

If not integrated, the voice store and forward facility traditionallyprompts the calling party to again enter the extension number of thecalled party and a code representative of whether the voice mailbox isto be accessed for deposit or retrieval of a message. Not only does thisrepresent an additional procedural burden on the calling party, butalso, in many cases, the performance of the voice store and forwardfacility is compromised. By this it is meant that if the calling partyhangs up prematurely without completing the deposit of a voice message,or if the calling party inadvertently forgets to dial a predeterminedstop code, the voice store and forward system may have to remain on-linean extended period of time to determine if an on-hook condition of thecalling party exists. This often occurs as some switching systemsgenerally do not transmit disconnect supervision signals to the voicestore and forward facilities. As a result, the voice store and forwardapparatus must monitor the telephone line for an additional period oftime, such as twenty to thirty seconds, as an indication of an on-hookcondition of the calling party.

From the foregoing, it can be seen that a need exists for a method andapparatus employed in connection with telephone switching systems tomore fully integrate voice store and forward functions with theswitching systems and thereby further facilitate the use thereof bycalling parties.

SUMMARY OF THE INVENTION

In accordance with the present invention, methods and apparatus aredisclosed which substantially reduce or eliminate the shortcomings andlimitations associated with prior art techniques. The call completionequipment of the invention provides a high level of integration betweentelephone switching systems and voice store and forward facilities.According to a preferred embodiment of the invention, on encountering abusy or no answer condition of the called telephone set, the callcompletion equipment of the invention consults a personality table toascertain whether the called extension is provided with voice store andforward options. On an affirmative indication, the calling party isprovided with a voice prompt to input a predetermined code, such as "*",if it is desired to deposit a message with the voice store and forwardfacility. The call completion equipment then consults a translationtable to find the call sequence according to which the call should beprocessed. The translation table includes information defining thedestination of the voice store and forward system, as well as theparticular voice mailbox to be accessed. In the event the voice mailboxdoes not correspond to the called extension number, as it may be, a callflow control is required.

The call completion equipment then consults a call flow control table todetermine the nature of the modification required to complete the callto the particular voice mailbox of the voice store and forward system.Also, additional call flow control tables may be provided in the eventthat a single telephone or PBX switching system subscribes to theservices of more than one voice store and forward facility.

In accordance with another feature of the invention, the call completionequipment of the invention can pass disconnect supervision signals tothe voice store and forward system, which feature was available only ifintegration was built into the telephone switching system. On-hookconditions of the calling party are thus quickly detected by the voicestore and forward facility, whereupon the input ports of such facilitycan be quickly switched to service other requests. A technical advantageof this feature is that fewer input ports of the voice store and forwardfacility may be required.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages will become more apparent from thefollowing and more particular description of the preferred embodiment ofthe invention, as illustrated in the accompanying drawings in which likereference characters generally refer to the same elements throughout theviews, and in which:

FIG. 1 is a block diagram illustrating an application in which theinvention may be advantageously practiced;

FIG. 2 is a detailed block diagram of the invention; and

FIGS. 3a and 3b illustrate in flow chart form a program flow executedthe call completion processor to provide the functions of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The application of the present invention is best understood by referringfirst to FIG. 1 of the drawings where the invention interconnected in atelecommunication network is illustrated. Particularly, the invention 10is shown as adjunct equipment 10 associated with a telephone switchingsystem, such as a private branch exchange (PBX) telephone system. Whilethe invention is ideally suited for use with an on-premises type oftelephone switching system 14, the illustrated application is not to beconstrued as a limitation to the uses of the invention. Moreover, theinvention may be integrated within many types of telephone switchingsystems, rather than being added on as adjunct equipment.

The telephone system 14 may be of the type which serves a plurality oftelephone sets 16, and which is equipped with a switchboard attendant18. The telephone sets may also be equipped with message waiting lamps17. The switchboard attendant 18 may be signalled to assist callingparties in completing calls to the telephone sets 16. Voice store andforward equipment 19 may also be utilized in conjunction with thetelephone switching system for allowing calling parties to deposit voicemessages when called parties are unavailable. The terms "voice store andforward facility" and "voice messaging facility" as used herein aresynonymous. As will be detailed more fully below, voice store andforward equipment allows persons to communicate back and forth bydepositing and retrieving voice messages. While the voice store andforward equipment 19 is shown connected to the telephone switchingsystem 14 such equipment could be constructed integral with suchswitching system, or could be remotely located and accessed through longdistance communication facilities. Messages deposited with the facility19 may be brought to the attention of the called party by illuminatingthe message waiting lamp 17 on the telephone set 16 assigned to thecalled party.

In one type of arrangement, the call completion equipment 10 isconnected to the central office 12 by one or more incoming trunks 20 onwhich telephone calls are directed to the telephone system 14. Incomingtelephone calls on trunks 20 are processed by the call completionequipment 10 and redirected to the on-premises system 14 bycommunication lines 22. Calls originated within the telephone switchingsystem 14 by one of the telephone sets 16 are processed by the telephoneswitching system 14 and redirected to the central office 12 on one ofthe outgoing trunks 24. The central office 12 is generally equipped withan interoffice trunk 26 for providing telephone communications to othercentral offices, or to tandem long distance switching equipment (notshown).

According to one mode of operation of the invention, all incoming callsfrom the central office 12 to the telephone switching system 14 arefirst intercepted by the call completion equipment 10 on incoming trunks20. In an alternate method of operation, calls can be received by theswitching system 14 and sent to the call completion equipment 10 overlines 22 which may be of the station or trunk type. Dialing informationreceived on incoming trunks 20 is processed by the call completionequipment 10 in a manner similar to that described in co-pending U.S.patent application Ser. No. 593,526, filed Mar. 26, 1984, and entitledPBX Intercept and Caller Interactive Attendant Bypass System. Accordingto the noted interactive system, there is transmitted a message over thetrunk 20 to the calling party, requesting the input of dialinginformation associated with a destination telephone set 16, e.g., thecalled party. On receipt of the digits dialed by the calling party, theinteractive system forwards such digits on the communication lines 22 tothe telephone switching system 14. The communication lines 22 may beconventional station lines, such as the types which connect thetelephone switching system 14 to the telephone sets 16.

The telephone switching system 14, whether it be a PBX, Centrex system,key system or other type of telephone system, is adapted to readilyrecognize the extension number transmitted over communication lines 22.In a conventional manner, the telephone switching system 14 willtransmit a ringing current to the telephone set 16 uniquely identifiedby the dialed digits. The telephone switching system 14 will alsotransmit audible ringing signals to the call completion equipment 10 viathe communication lines 22. The telephone switching system 14 willcontinue to ring the selected telephone set 16 until the called partyanswers. In the event that the selected telephone set 16 is alreadyoff-hook, and is thus being currently used by the called party, thetelephone switching system 14 will return a busy signal to the callcompletion equipment 10 by way of the communication lines 22. Theaudible ringing and the busy signals supplied by the telephone switchingsystem 14 over the communication line 22 constitute call progress tonesfor alerting the calling party as to the status of the call which isattempted to be completed.

The call completion equipment 10 makes provisions for both of thoseinstances in which the destination telephone set is not answered inresponse to an incoming call, and in which the destination telephone isoff-hook, indicating the called party is busy. In one mode of operationof the present equipment, the calling party is given a choice ofoptions, one of which includes leaving a message for the unavailablecalled person. This contrasts with prior art devices wherein sometelephone switching system did not provide such an option, butautomatically forwarded calls to a voice store and forward system viainherent software which allowed integration only with voice store andforward systems which were specifically designed to accommodate suchswitching system proprietary signalling.

It is not only an object of the present invention to provide the callingparty with options, but also it is another object of the presentinvention to provide integration with a wide range of telephoneswitching systems and voice store and forward systems not otherwisedesigned for this integration.

The call completion equipment 10 shown in FIG. 2 is provided with aninput port 28 connected to the incoming trunk 20. An output port 30 isconnected to the communication line 22. The input port 28 and the outputport 30 are transformer coupled by respective transformers 32 and 34 toa switching network 36. A pair of loop closure relay contacts 35 and 37are independently operable to provide a closed loop to the respectiveincoming trunk 20 and the communication line 22. The loop closuressignal the switching systems connected thereto of acknowledgements andrequests for service. An outpulser 39 is bridged across thecommunication line 22 and is operable to outpulse a telephone number,either by DTMF signalling or by dial pulses, under control of othercircuits of the call completion equipment 10. The switching network 36is operative to couple the input transformer 32 either to the outputtransformer 34, or to a hybrid 38. A ground and ring detect circuit 40is coupled to the input port 28 for detecting ground and ringingindications transmitted by the central office 12 on the incoming trunk20.

The switching network 36 is connected to the hybrid 38 by abidirectional conductor 42. The hybrid 38 is connected by aunidirectional outgoing conductor 44 to a first switching stage 46 andto a DTMF detector 48. The detector 48 is of conventional design and canprovide an output responsive to the detection of the standardized DTMFsignals transmitted by non-rotary type telephone sets. An integratedcircuit suitable for use as a DTMF detector is identified as type 8870,and obtainable from Mitel Corporation. Dial pulse receivers can be usedin combination with the DTMF detector 48, or in lieu thereof, to respondto digits dialed from a rotary-type telephone set. Speech recognitioncircuits which are still costly and still being perfected can be usedwith equal advantage as either the DTMF or rotary dial detection types.The first switching stage 46 is effective to selectively switch signalscarried by the unidirectional outgoing conductor 44 to a pair of callprogress tone detectors 50 and 52. Circuits suitable for call progresstone detection are identified as integrated circuit type LM 67, andobtainable from National Semiconductor. While each call progress tonedetector 50 and 52 is effective to detect call progress tones, thefollowing description will proceed assuming that the first switchingstage 46 couples tones from conductor 44 to detector 50.

A message storage unit 54 for storing a plurality of prompt messages isswitchably connected by a second switching stage 56 to an input port 58of the hybrid 38. With this arrangement, prompt messages can betransmitted through the hybrid 38 in one direction, and call progresssignals can be simultaneously received by the call progress detector 50through the hybrid 38 in an opposite direction. The message storage unitis connected to the switching stage by bidirectional buses so thatinformation can also be input into the storage unit 54 via the inputports of the call completion equipment 10. With this capability, a callcompletion equipment administrator can affect a change, addition ordeletion of the data stored within the storage unit. The administratorcan, for example, place an incoming call to the call completionequipment 10 and by a code, or other means, place the equipment in amode for accessing the storage unit 54 and changing the contentsthereof. The switching stage 56 includes another input for switching asource 57 of analog music or voice announcements therethrough to thecalling party. This may be accomplished, for example, during periods oftime when the calling party is placed on hold or camp-on by the callcompletion equipment 10.

The call completion equipment 10 further includes a processor complex 72for controlling all the electrical apparatus of the invention accordingto a software program. Timing and synchronization of all the electricalapparatus is controlled by many clock phases according to the systemtiming 73. The processor complex 72 includes a microprocessor 74connected by a bidirectional bus 76 to a memory 78, including RAM andROM storage areas. The memory 78 also includes various look-up tablesdescribed below. The bidirectional bus 76 is shown in simplified form,but in practice may include multiple bidirectional buses for carryingaddress and data information between the microprocessor 74 and thememory 78. Also included in the processor complex 72 is an interface 80by which the microprocessor 74 can control the other electrical circuitsof the call completion equipment 10.

A communication bus 82 couples signals between the microprocessor 74 andthe interface 80. The interface 80 provides a plurality of outputs 84,each of which is connected to electrical circuits controlled by themicroprocessor 74. For example, the microprocessor 74 receivesinformation from the ground and ring detector 40 through the interface80 indicating when ground and ringing conditions are present on theincoming trunk 20. The processor complex 72 can then execute appropriateinstructions of its program to respond to the noted signals on theincoming trunk 20. The interface 80 is also connected to the variousswitching networks and stages 36, 46 and 56 so that various electricalpaths can be established to route information to desired equipment inthe call completion equipment 10. In a similar manner, the messagestorage unit 54 is processor controlled through the interface 80 totransmit appropriate messages through the second switching stage 56 tothe calling party. The other circuits of the call completion equipmentare controlled by the processor complex 72 in the manner described belowwith the software flow charts.

Stored in the memory 78 of the processor complex 72 are various tablesreferred to by the microprocessor 74 during the processing of anincoming call on trunks 20. A voice store and forward messaging tablesection 85 includes those telephone extension numbers which are providedwith voice messaging features. A digit translation table 86 may beconsulted to automatically translate one extension number into another,such as is done with a call forwarding feature. A camp-on table 87 maybe interrogated to ascertain whether an automatic camp-on functionshould be invoked in connection with predetermined telephone extensionnumbers. A tone learn program 88 may be employed to obtain and store thesignature of call progress tones transmitted by the tone generator ofthe telephone switching system 14.

The call completion equipment 10 processes an incoming call from acentral office 12 and redirects the telephone call to the telephoneswitching system 14 using the circuits as shown in FIG. 2, as controlledby the processor complex 72 in the manner shown by the flow charts ofFIGS. 3a and 3b. More specifically, the flow charts illustrate asituation in which a call directed to the telephone switching system 14causes a selected telephone set 16 to be rung, but such set is notanswered by the called party. The processing of busy and no-answer callsis addressed in co-pending application entitled "Busy/No-Answer CallCompletion Equipment", Ser. No. 909,755, filed Sept. 22, 1986. As notedabove, the busy/no-answer situation occurs frequently, with the resultthat the calling party generally has no alternative but to hang up andattempt to complete the call at a later time. Other sophisticatedsystems, such as identified above as "PBX Intercept and CallerInteractive Attendant Bypass System", provide an automaticnondiscretionary connection of the calling party to an attendant afterit is apparent the called party is not going to answer.

Block 90 of the FIG. 3a flow chart indicates an initial program locationto which the microprocessor 74 is directed for responding to requestsfor services received from the central office 12 over the incoming trunk20. It should be understood that the incoming trunk 20 is merelyexemplary of requests from parties originating a telephone call, as suchrequest may originate from other types of lines, equipment or switchingsystems. Decision block 92 illustrates a decisional program loop inwhich the microprocessor 74 routinely monitors the ground and ringdetector 40 by repetitively interrogating an associated appearance onthe interface 80. Depending upon the type of incoming trunk 20 employed,a request for service may be in the form of a conventional ringingsignal from the central office 12, or a ground applied to the tipconductor of the trunk 20. When such a request for service is detectedby the detector 40 and presented to the microprocessor 74 by way of theinterface 80, the incoming ringing is tripped by closing the trunk loop20. The microprocessor 74 causes switch contacts 35 to be closed,thereby seizing the trunk 20 and allowing loop current to flowtherethrough. As a result, the central office 12 detects the trunk loopclosure and terminates the ringing signal.

Next, and according to flow diagram block 96, the processor complex 72causes a connection to be established in the switching network 36 forconnecting the incoming trunk 20 to the hybrid 38. The processor complex72 also monitors the output of the DTMF detector 48 for DTMF dialingsignals, and the output of the call progress tone detector 50 forprogress tones. Block 98 represents the processor complex functionswhich select an appropriate message from the message storage unit 54,establish a connection in the switching stage 56 and transmit theselected message through the hybrid 38 and network connection 36 to thecalling party over the incoming trunk 20.

The specific operations and apparatus for accomplishing this is setforth in more detail in the noted co-pending applications, the entiresubject matter of which is incorporated herein by reference. Pursuant tothe transmitted message, the calling party can dial the telephoneextension number of the called party with whom communications aredesired, without the need of the services of the telephone switchingsystem switchboard attendant 18. It should be noted that in the casethat the incoming trunk lines 20 are of the direct inward dial (DID)type, the receipt of address and destination information beginsautomatically after trunk seizure and handshaking according to methodswell known in the art. In this case, a transmitted message instructingthe calling party to send a telephone extension is not necessary. Block100 of the flow chart indicates the decisional block as to whether thedigits of the extension number have been received. Such digits are alsostored for later use in identifying a particular voice mailboxassociated with the called party. Voice store and forward facilities 19generally provide a number of voice mailboxes, each identified by adigit sequence, such as a telephone extension number. In other types ofvoice store and forward facilities, the voice mailboxes numbers may notcorrespond to the extensions of the called parties.

A timeout 102 of a predetermined period of time is established in theprogram to form a window in which the dialed digits can be received. Ifthe calling party dials no information within this predetermined periodof time, and if the incoming trunk is yet seized 104, control of themicroprocessor 74 is branched to block 106 where the identification of adefault answering position is loaded into a processor register. In theexample, the default answering position is the switchboard attendant 18.

In accordance with the flow diagram, the program is branched from block106 to 108 to establish a talking path between the default answeringposition 18 and the calling party. In other words, in the event that thecalling party does not dial any digits in this time period, and does notgo on hook, automatic assistance is provided by the connection to theswitchboard attendant 18 or some other predesignated default. In somesituations, such as after office hours, the processor 72 canautomatically load the directory number of the voice messaging facility19 in a register, whereupon, in encountering block 106 the callcompletion system 10 would be prepared to outpulse digit information forconnecting the calling party directly to the voice messaging facility19. With reference back to block 104, there is shown a situation inwhich the calling party may go on-hook during or after the transmissionof the initial instructional message 98. In the event the calling partygoes on-hook, i.e., abandons the call, the network connection is removed110, the trunk is released 112 and control of the microprocessor 74 isreturned 114 to the start 90 of the program.

With reference again to block 100 of the FIG. 3a flow chart, programcontrol of the microprocessor 74 is transferred to block 108. The PBXcommunication line 22 is seized by closing the contacts 37 bridgedacross the line 22. This is a conventional signal to the telephoneswitching system 14 of a request for service on the communication line22.

The digits received from the calling party by the DTMF detector 48 areloaded 116 into a temporary register for subsequent transfer to thetelephone switching system 14. The output of the DTMF detector 48 isthus switched to the incoming trunk 20 and made available to theprocessor complex 72 to determine which pair of tones are received, andfor determining the corresponding digit. The call progress tone detector50 is monitored by the microprocessor 74 to decode the specific type ofcall progress tone received. With this switched arrangement, the callprogress tone detector 50 processes the signals output by the hybrid 38to determine the nature and type of signal received.

The functional features of the call progress tone detector 50 isdescribed in the co-pending application entitled "Busy/No-Answer CallCompletion Equipment". Other conventional call progress tone detectorscan be utilized. Nevertheless, it is sufficient to understand here thatthe call progress tone detector 50 can distinguish between many signalsincluding a busy status or a ringing status of the called telephone set16. When the call progress tone detector 50 is connected as described,it can monitor progress signals generated by the telephone switchingsystem 14 as transmitted to the call completion equipment 10 on thecommunication line 22.

According to block 116, the default answering position's telephonenumber previously loaded into the register is outpulsed by pulser 39over the communication line 22. To be described in more detail below,the invention also makes provisions for accessing the voice messagingfacility 1 utilizing the outpulser 39 under control of the processor 72.The telephone switching system 14 establishes a connection pursuant tothe attendant's telephone number between the communication line 22 andthe attendant 18.

According to block 120, if a busy signal is detected by the callprogress tone detector 50, control is branched to flow block 122 wherethe caller's option is set to include a busy case. This information isutilized later in completing the call. From block 122 the programdirects the processor 72 to entry point A which will be described below.In the event that a busy signal is not detected, then control isbranched to block 124 where the communication line 22 to the calledparty is monitored to determine if the called party has answered in theallotted period of time. If an affirmative indication is detected, thetone detector is released 126 and the program flow is returned 128 tothe start. When the called party answers within the allotted period oftime, the telephone switching system 14 is connected to the trunk 20 andthe called party is thus connected to the calling party.

When it is assumed that the called party associated with the telephoneset 16 is not going to answer, and that further ringing is futile, thecaller's option is set to include a no-answer case. This is illustratedin program flow block 130.

One skilled in the art would recognize that the processing describedherein is time-shared among a plurality of calls and that thedescriptions of control branching is to be taken figuratively, ratherthan literally. When the line of the called party continues to ring, themicroprocessor 74 determines whether the telephone set 16 has been runga predetermined length of time. The length of time the called telephoneset 16 is rung before further action is taken is arbitrary, and thus canbe adjusted or specified according to a personality table described inmore detail below. Beyond this length of time, it can be assumed thatthe called telephone set 16 will not be answered.

The program entry point A illustrates a case when the calling partycannot reach the desired called party, and default assistance isautomatically invoked. A message can be transmitted to the calling partyincluding information concerning the situation in which the calledtelephone set 16 cannot presently be reached, but that the telephonecall may be completed to a secondary destination by alternative means.For example, the calling party may be assisted by completing a call toanother party associated with the telephone switching system 14, or bythe assistance of the switchboard attendant 18, or by verballydepositing a message using the voice store and forward messagingfacility 19.

Communication exchanges may be equipped with voice messaging apparatuswhich provides an indirect exchange of communications, without theconcurrent exchange of messages. In other words, one party may call apredetermined telephone number and leave a recorded voice message foranother party. The other party may later call the number and retrievethe message, and also leave a response. This type of communicationtechnique is described in U.S. Pat. No. 4,371,752. However, not allparties subscribe to or have available to them the optionalcommunication through voice store and forward messaging facilities.Thus, the call completion equipment 10 of the invention must determine,as is shown in program block 132, whether the called party has a voicemessaging option. This is determined by consulting a personality tablewhich resides in the memory of the processor 72. If this determinationis in the negative, a special message is selected 134 from the messagestorage unit 54 and transmitted to the calling party. This message willinstruct the party as to the dialing of an alternate telephone extensionnumber, or as to some default assistance. If, on the other hand, thevoice messaging option is available to the called party, a differentmessage is selected 136 in the message storage unit 54 for transmittalto the calling party. This message includes the same informationalcontent as that noted in block 134, and in addition advises the callingparty that the voice messaging option is available.

The communication line 22 to the telephone switching system 14 isreleased 138 and the call completion equipment 10 awaits for thetransmission of digits from the calling party. If digits are notreceived 140 within a timeout period 142, and if the trunk 20 is yetseized by a calling party, the processor 72 loads 144 the telephone ordirectory number of a new called party into the processor register Thenew called party's number is preassigned and can be automaticallychanged depending on a number of considerations. For example, at night,the new called party's number might be the directory number of the voicemessaging facility. During the day it might be the switchboard attendant18, or it might be the voice messaging facility if a certain party'sline is called, whereas if other lines are called it would be theswitchboard attendant. It is important to understand that a generalvoice mailbox of the messaging facility 19 may be designated to whichdefault calls are directed. With this arrangement, an operator or personcan routinely retrieve voice messages deposited therein and thensubsequently redistribute the messages to the appropriate calledparties.

The receipt 140 of digits by the DTMF detector 48 is accompanied by thetranslation 146 of such digits to determine whether an alternate numberor the default answering position number has been dialed, or whether thevoice messaging option has been indicated. The receipt of a four digitnumber generally signifies a particular extension number associated witha particular telephone set 16. If a valid alternate extension number hasbeen dialed 148 by the calling party, it is loaded 150 into a registerfor subsequent outpulsing. If the digits received from the calling partycannot be identified as a valid alternate extension number, the digitsare next checked 152 to determine if a default answering positionnumber, in the nature of a switchboard attendant 18, has been received.The instructional message transmitted according to block 136 willgenerally specify what digits should be dialed in order to be connectedto the telephone switching system default answering position callcompletion assistant.

Generally, it is only necessary to dial the digit "0" to obtain theassistance of a switchboard attendant, or some other similar defaultanswering position. The instructional message transmitted to the callingparty will indicate the digit or digits to be dialed for connection tothe default answering position 18. While a representation of the digit"0" may be loaded 154 directly into the register, an intermediatetranslation may be conducted in accordance with the translation table86. For example if call completion assistance is being handled by atelephone set other than the switchboard 18, then the telephone numberof the other set can be loaded into the register 104 instead of theswitchboard designation "0". This aspect is advantageous when aswitchboard attendant 18 is not available, such as during lunch or atnight, calls can still be completed to an alternate destination, such asa guard station or the like.

If neither an alternate extension number 148 nor a default answeringposition number 152 have been received and decoded by the DTMF detector48, the digits received are next checked to ascertain if the calledparty is allowed 156 voice mail, e.g., has a voice mailbox, or if thecalling party has selected 158 the voice message option. On a negativedetermination of either of these conditions, the switchboard attendant'snumber is loaded 154 and outpulsed.

The instructional message transmitted pursuant to flow chart block 136will inform the calling party as to the manner in which access can behad to the voice messaging facility. While arbitrary, the instructionalmessage can specify that the dialing of the "*" symbol will be decodedas an instruction to connect the calling party to the voice messagingfacility 19. If the dialed digit or digits received from the callingparty signify the voice message option 158, an appropriate directorynumber is loaded into a register for subsequent outpulsing to thetelephone switching system 14. A translation of the voice messagedesignation symbol is made, and the translated number is loaded into theregister. The translated number will be a directory number whichuniquely identifies the destination at which the voice messagingcapability can be accessed. For example, if the voice messaging facility19 is co-located with the telephone switching system 14, then suchfacility can generally be accessed simply by dialing an extension-likenumber. The telephone switching system 14 will process this number andpermit access to the voice messaging facility 19.

If, on the other hand, the voice messaging facility 19 can only bereached by a long distance communication, then such an appropriatenumber is loaded into the register. As an additional example, a twelvedigit number may be loaded into the register to reach an outgoing trunk24 so that a long distance call can be established. The twelve digitnumber may include the digit "9" to obtain an outside line, a "1" tosignify a long distance call, an area code and a seven digit telephonenumber. Of course, many other digit translations may be affected toconnect the calling party directly to a remote voice messaging facility.

Situations may arise in which the digits received from the calling partycomprise neither an alternate extension number, a switchboard attendantnumber nor a voice messaging designation. An erroneous telephone numbermay have been inadvertently dialed by the calling party. In this event,a message is selected in the message storage unit 54 and transmitted tothe calling party. This message may include informational contentindicating that the telephone call cannot be completed as dialed, butthat the calling party should redial the number. Control is thenappropriately branched to again process the dialed digits, if any,received from the calling party.

In brief summary, it can be seen from the foregoing that with theprovision of the call completion equipment 10, many alternatives areavailable to the calling party for completing a secondary telephonecall, even though the primary called party cannot be reached. This ishighly advantageous in view that the ability to communicate is importantto businesses. It is also important to appreciate that the callcompletion equipment 10 can be connected to a telephone switching system14 with little, if any, modification to such switching system. As aresult, the combining of the features of the call completion equipment10, together with the those of the telephone switching system 14provides additional communication capabilities not heretofore realized.

The call completion equipment 10 can also assist in completing atelephone call when the telephone set 16 of the called party isoff-hook, and the called party is therefore busy. The program flow chartof FIG. 3b is reached from an affirmative determination of decisionalblock 158 (FIG. 3a). According to program flow block 160, the processor72 consults a call flow control table to define a message leavingsequence. As will be described in more detail below, such a sequence mayinclude the directory number of the voice messaging facility, a codeindicating a message retrieval or deposit, other codes indicating pausesor wait for disconnects, etc.

As noted in block 162, and pursuant to the call sequence, the PBX ortelephone switching system 14 is seized. The directory number of thevoice messaging facility is then outpulsed 164 to the telephoneswitching system 14. In a conventional manner, the telephone switchingsystem receives the directory number on communication line 22, whereupona path is established between such communication line 22 and theoutgoing PBX line connected to the voice messaging facility 19. A testis conducted 166 to determine if the voice messaging facility 19 isbusy. If so, the program flow is branched back to the beginning of block160. In the event the voice messaging facility 19 is not busy, anotherdetermination is made as to whether the voice messaging facility 19 hasanswered 168 the call. Busy and answer signals are detected in themanner described above. If the voice messaging facility 19 does notrespond to the request for service, program control is branched back toflow block 160.

When the voice messaging facility 19 responds to the request forservice, an inquiry is made into the internal tables of the callcompletion equipment 10 as to whether the voice messaging facility 19requires a code for depositing 170 a message. If such a code isrequired, the call completion equipment 10 responds by transmittinginformation to the voice messaging facility corresponding to the codefor depositing a message. Other codes may be required if it is desiredto retrieve a message from the voice messaging facility. Of course, ifno such code is required, the processor 72 is directed from block 170 toblock 174. The decision block 174 encompasses those steps taken by theprocessor 72 in determining whether the voice mailbox number is the sameas the extension number initially dialed by the calling party. If suchnumbers are the same, program control is branched to block 178. On theother hand, if the voice mailbox number is different from the calledparty's extension number, a translation is made 176 from the extensionnumber to the voice mailbox number, using the selected call flow controltable.

Next, the voice mailbox number is transmitted 178 to the voice messagingfacility via the telephone switching system 14. A two-way connection isestablished 180 between the calling party and the voice messagingfacility 19. In a conventional manner, the call completion equipmentwaits for a disconnect 182, signifying the termination of the voicemessage deposit. The nature in which disconnect information is detectedand transmitted by the call completion equipment 10 will be described inmore detail below.

On the detection of a disconnect by the calling party, the processor 72consults 184 the call flow control table to determine if an end of callcode is required by the voice messaging facility 19. If no such code isrequired, the incoming trunk 20 is idled 188, as well as thecommunication line 22 connected to the call completion equipment 10. If,on the other hand, such an end of call code is required, the callcompletion equipment 10 loads such code into the register, and outpulsesthe same to the voice messaging facility 19 to signal such facility thatthe voice message deposit has been terminated. After the call completionequipment 10 idles the incoming trunk 20 and the communication line 22,return is made 190 to the beginning of the call processing flow chart.

With the foregoing system operation, calling parties are provided withalternative secondary destinations when the primary destination is busyor does not answer. The call completion equipment 10 provides acapability for enabling the calling party to selectively choose varioussecondary destinations for completing the call.

Having set forth the general operations of the call completion apparatusof the invention, the detailed operation thereof with respect to theintegration of the voice store and forward features and PBX systems isset forth below. Detailed Tables I-VI in the Appendix correspond totable 85 (FIG. 2) used with the voice messaging facility 19. TablesI-III depict the general type of information found in the look-uptables, while Tables IV-VI illustrate examples of look-up table 85entries for a typical installation. Each customer utilizing the callcompletion equipment of the invention would have tables configuredpeculiar to the desired needs. Particularly, Table I is a "personalitytable" having various parameters which govern the processing of eachcall associated with an incoming trunk 20 directed to the callcompletion equipment 10. Each incoming trunk 20 is associated with apersonality table which defines the characteristics of calls made onsuch trunks.

Table II illustrates a translation table which is utilized in invokingthe services of the voice store and forward facility 19, and inparticular defines a set of parameters which are used to request serviceof the voice store and forward facility 19, define whether a message isto be retrieved or deposited and define the particular voice mailbox inwhich it is desired to deposit or retrieve a voice message. Moreparticularly, the digit translation table includes entries concerningdigits which are to be matched with dialing information input by thecalling party, a number of selectable call sequences which define theparticular sequence for accessing and utilizing the voice store andforward facility 19, as well as an index for directing the processor 72of the call completion equipment 10 to a number of other tablesidentified as call flow control tables. Table III illustrates theentries of a call flow control table which are utilized in modifyingdestination determining information input by the calling party beforesuch modified information is output to the voice store and forwardfacility 19, or more generally, before such information is used tocontrol the flow of steps of processing a call.

After intercepting requests for service by the call completion equipment10, the processor 72 identifies the particular incoming trunk 20carrying the request for service. As noted above, each incoming trunk 20is associated with a particular "personality". The personality tableincludes an entry which directs the processor 72 to a predefinedtranslation table which, based upon the digits received from the caller,or lack thereof, defines a call sequence to be executed for completingthe particular telephone call. The personality table also includes anadditional entry which specifies whether an outside party can makeadditional calls to the telephone switching system 14 without goingon-hook, but after the inside party has gone on-hook.

According to other personality table entries, recall personalities aredefined, as well as immediate, delay, transfer or direct modes. Thenature and extent of a delay is also specified in which an operator orswitchboard attendant 18 may respond to an incoming call before anautomatic response by the call completion equipment 10. The personalitytable also specifies the type of message prompt to be transmitted withnew, incoming telephone calls; the time which can elapse between callingparty dialing in response to a message before a default occurs; anddefault telephone numbers to which the calling party is automaticallydirected for assistance. An additional entry to the personality tablemay include entries defining whether camp-on options are allowed withrespect to the particular incoming trunk 20 and the number of times abusy extension telephone 16 may be retried before transmitting a messageto the calling party. Lastly, the exemplary personality table defines anentry which specifies whether music is to be transmitted to the callingparty when in a hold or camp-on condition. The foregoing personalitytable entries are only exemplary of the many characteristics which maybe ascribed to a telephone call. It is well within the ambit of thoseskilled in the art to provide additional entries to further definecharacteristics to be associated with particular incoming lines.

The translation table Table II comprises a first section which includesa number of entries corresponding to destination determining informationdialed by calling parties. Generally, the entries in Section 1 of TableII will include all of the telephone extension numbers serviced by thetelephone switching system 14 and any other single or multiple digitseries utilized by the telephone switching system 14 or the voice storeand forward facility 19 in servicing calling parties, whether insideparties or outside parties. When the processor 72 of the call completionequipment 10 consults Section 1 of the translation table for a matchbetween an entry therein and a dialed number, and if no such match isfound, the call completion equipment 10 will send the call to thedefault destination specified in the personality table. It can be seenthat Table II includes in Section 1 thereof, blocks of entriescorresponding to extension numbers, and various single digit entries,such as "6" and "7" denoting codes associated with the voice store andforward facility 19 for indicating respectively whether it is desired toretrieve a message and leave a message.

On determining a match between a dialed number and an entry in Section 1of Table II, the processor 72 of the call completion equipment 10proceeds to Section 2 of Table II, wherein a call sequence is selected.Each entry in Section 1 is associated with a call sequence such thatwhen a match is found by the processor 72, one of the call sequences isautomatically selected. As can be seen from the call sequences of TableII, Section 2, the various sequences define the various operations bywhich the processor 72 can direct a call toward completion. Routineincoming telephone calls handled by the call completion equipment 10 arecarried out using call sequence no. 1, namely, Send Dialed Digitsreceived from the calling party directly to the telephone switchingsystem 14, with or without modification thereof. Call sequence 15 isdirected to a call flow treatment in which a different personality tableis consulted, as well as a retranslation of digits received to provide anew set of destination determining information transmitted to thetelephone switching system 14. Call sequence 16 will be described inmore detail below in connection with converting an extension numberdialed by a calling party into a voice mailbox number associated withthe called party having the same extension number.

Table III is illustrative of a call flow control table indexed by anentry in Section 3 of the translation table, Table II. The call flowcontrol table includes a number of entries utilized by the callcompletion equipment 10 to control the flow of the call to the telephoneswitching system 14 as well as to change the string of digits receivedfrom the calling party before transmitting a resulting modified stringof digits to the telephone switching system 14. It should be understoodthat when the directory number of the voice store and forward facility19 is input to the telephone switching system, such facility isconnected to the call completion equipment 10. Thus, any digitthereafter input to the switching system is transferred directly to thevoice messaging facility 19.

Each of the noted call flow control entries comprises a code having acontrol code and possible mode change codes. For example, the call flowcontrol entry "9F1800C02232727" is interpreted as follows, proceedingfrom the left to the right of the code. The first digit indicates thedigit 9 is to be sent by the call completion equipment 10 to thetelephone switching system 14. The alphabetic character "F" indicates apause allowing the telephone switching system time to seize an outgoingtrunk, while the next digit string "1800" is the next series of digitsto be sent. The mode change code "CO" directs the processor 72 to changefrom a tone transmission mode to a rotary pulse transmission mode. Thedigits "2232727" are thus sent by rotary pulse techniques to thetelephone switching system 14.

A control code "ClXX" directs the processor 72 to retranslate dialeddigits for sending to the telephone switching system 14. This call flowcontrol table entry is of the type utilized to supply the voice storeand forward facility 19 with a voice mailbox number derived from thereceived extension number. According to this 4-digit control code, thedigits are collected and caused to be retranslated according to atranslation table defined by two digits occupying the "XX" digitpositions. As can be appreciated, the invention may include manytranslation tables, and may be utilized in connection with a specificcall for inserting the table number in the "XX" position of the notedcontrol code. The result thereof is inserted in the outpulsed digitstring in place of the control sequence. Translation table 00 placed inthe "XX" position refers to a current personality translation tableassociated with the call.

It is important to understand that the translation of digits receivedfrom the calling party can be carried out in connection with differenttranslation tables than were used when the digits were first received bythe call completion equipment 10. This feature facilitates theflexibility of the call completion equipment 10 for those instances inwhich the voice mailbox number is not identical to the called party'sextension number, or for cases in which the call completion equipment 10is required to select one of several different voice store and forwardfacilities. Also, as an error check, nonexistent translation tables andunmatched dialed digits are effective to remove the control sequencefrom the outpulsed digit stream, and insert blanks or spaces in lieuthereof. Also, the control sequence "ClXX" places digits anywhere in theoutpulsed bit stream based on the dialed number. Several distinctpatterns based on a dialed number may reside in a single entry in thecall flow control table. For example, the directory number of the voicestore and forward facility 19, the voice mailbox number and a messagewaiting lamp directory number may be specified for each telephoneextension of the telephone switching system 14.

The control sequences noted in the translation table may also be nested.In other words, the digits inserted after a retranslation may containcontrol sequences, including the "CIXX" sequence, which causes yet anadditional retranslation of the sequence. After inserting the result ofthe retranslation and storing the same in a buffer, scanning of thedigits to be outpulsed continues in order to locate the various controlsequences. Importantly, the search for retranslation control sequencesproceeds from right to left, namely, from the last digit entered in thebuffer which stores the sequence. Any digit deletion specified by aretranslation occurs from the succeeding digits, which may themselveshave been a product of a retranslation, thus mimicking a calling partydialing the succeeding digits. More sophisticated applications of thepresent invention may utilize this feature.

The "C2" control sequence allows the call completion equipment 10 towait for an answer from the telephone switching system 14. This controlsequence is utilized to ensure that the voice store and forward facility19 answers before the call completion equipment 10 transmits subsequentdigits, such as the voice mailbox number. In this event, if the callcompletion equipment 10 is connected to the telephone switching system14 via a direct inward dial (DID) circuit, the call completion equipment10 will immediately recognize an answer from the voice store and forwardfacility 19. On the other hand, if the call completion equipment 10 isconnected to the telephone switching system 14 by station lines orcircuits, then the call completion equipment 10 will recognize andanswer after one of the following three events occurs. (1) A ringbacktone is absent for at most two complete ringback cycles or isinterrupted during a ringing cycle, (2) the call completion equipment 10detects a dual tone multifrequency (DTMF) digit, of (3) the callcompletion equipment 10 detects a tone from the voice store and forwardfacility 19, such tone having a predetermined length. Preferably, thefrequency of the tone should be 350, 440, 480 or 620 hertz, and shouldnot be one of the tones provided by the telephone switching system 14for busy or ringback purposes.

The C2 control code accommodates the situation in which the voice storeand forward facility 19 does not answer during a ringback tone cycle.This has the obvious effect of significantly slowing the process ofdepositing a voice message with such facility. To avoid thisshortcoming, and in those cases in which the call completion equipment10 is connected to the telephone switching system 14 by a station lineinterface, either a DTMF digit or a tone, as noted above, should berecorded on the individual voice prompts of the voice store and forwardaudio response equipment. Thus, as soon as the voice store and forwardfacility 19 responds to a request, the DTMF digit or tone is transmittedthrough the telephone switching system 14 to the call completionequipment 10. Most voice store and forward machines provide thecapability for recording such a tone or signal. In this manner, andaccording to the invention, the prerecording of a tone or signal inconnection with a voice store and forward response functions to speed upthe process of automatically reaching the voice store and forwardfacility 19, if such equipment does not answer during a ring, or in theevent the call completion equipment 10 is not connected to the telephoneswitching system 14 via DID trunks.

In addition, the C2 control wait for telephone switching system answertemporarily suspends outpulsing of destination determining informationwhile the call completion equipment is waiting for an answer from thevoice store and forward facility 19. When the call completion equipment10 is connected to the telephone switching system 14 or by a DID trunk,reverse battery indications or other call progress tones are detected,and the call completion equipment 10 proceeds in outpulsing destinationdetermining information to the voice store and forward facility 19.

In accordance with another feature of the invention, the call completionequipment 10 interrupts the communication path between the calling partyand the telephone switching system 14 while outpulsing is suspended dueto the C2 wait for answer control code. Without this interruption in thecommunication path, the calling party would hear audible ringback tone,and perhaps an undesirable initial audio prompt from the voice store andforward facility 19, followed by silence during the resumed outpulsingby the call completion equipment 10. This can be appreciated as the callcompletion equipment 10 provides the appropriate voice mailbox number tothe voice store and forward facility 19, and thus the superfluous prompt"Please enter your mailbox number" by the voice store and forwardfacility 19 is prevented from reaching the calling party. This is animportant aspect of the present invention since it presents the callingparty with a continuous and logical flow of a call handled by both atelephone switching system and a voice messaging system. This logicalflow is one of the elements of the integration. In the event the voicestore and forward equipment 19 has already answered before the C 2 Waitfor Answer control sequence is encountered, outpulsing by the callcompletion equipment 10 proceeds after such control sequence, withoutwaiting.

In brief summary, the C2 control code is utilized to ensure that thevoice store and forward facility 19 responds to a request for servicebefore the call completion 10 transmits the required voice mailboxdigits. As an alternative to utilizing the C2 control code, the callcompletion equipment 10 may be programmed with pauses in order toprovide sufficient time for the voice store and forward facility 19 toanswer.

Yet another control sequence is a "C3" code which functions to wait fora disconnect from the calling party or a disconnect from the telephoneswitching system 14. The utilization of this control code by the callcompletion equipment 10 permits conventional voice store and forwardfacility 19 to operate more efficiently. Most, if not all, voice storeand forward facilities provide an initial voice prompt requesting thecalling party to dial or input a code when the message deposit iscomplete. Since most voice store and forward facilities are usuallyconnected to on-premises telephone switching systems 14, and notdirectly to the central offices 12, there is no direct signal whichinforms the voice store and forward facility that the voice messagedeposit is completed. This frequently occurs if the calling party goeson-hook, and forgets to enter an "end of call" code. In such event, mostvoice store and forward facilities detect a silence period for about 20to 30 seconds before the input port of the voice store and forwardfacility 19 is released. As a result, the input ports of the voice storeand forward facility 19 are unnecessarily tied up and not able toservice other parties who may want to deposit or retrieve voicemessages. In addition, needless memory storage area may be wasted in thevoice store and forward facility for storing the additional 20-30seconds of silence if silence compression is not a feature of the voicestore and forward facility.

The call completion equipment 10 is ideally employed in connection witha central office 12 and incoming trunks 20. Such trunks 20 may beadapted to provide ground start or loop start signalling to indicate anon-hook condition of the calling party. In such an event, the callcompletion equipment 10 can detect such signalling and transmit amessage and/or other call complete code to the voice store and forwardfacility 19 to provide a speedy indication of a completed call. Theholding time of the voice store and forward facility 19 is therebyminimized, and such input ports can be freed to service other requestsfor the storage or retrieval of voice messages. With voice store andforward facilities 19 servicing high volumes of external incomingtraffic, the provision of the transmission of speedy disconnect signalthereto can increase the efficiency of such system to the extent thatfewer input ports may be required.

While the two-digit C3 control sequence is embedded in a series of otherdigits or control sequences, the processing of such a control sequenceis effective to temporarily suspend outpulsing of digit informationlocated to the right thereof in the sequence. The outpulsing of theremaining portion of the digit sequence is suspended until a disconnectof the calling party or the telephone switching system 14 is detected.After detecting a disconnect, the call completion equipment 10 outpulsesthe remaining digits of the sequence. In the event there is detected aline disconnect on the telephone switching system side of the callcompletion equipment 10, the subsequent outpulsing by the callcompletion equipment 10 is obviously not performed by such callcompletion equipment 10.

The C3 control code can also be used in conjunction with a C4 controlcode, to be discussed in more detail below, to allow the call completionequipment 10 to wait until the voice message deposit is completed,whereupon the call completion equipment 10 can transmit a code to thetelephone switching system 14 to illuminate a telephone set lamp 17indicating a message waiting condition. Preferably, the C3 control code(Wait For Answer) sequence should generally appear prior to a Wait ForDisconnect to assure that the latter is processed and not ignored due tothe absence of an answer from the telephone switching system 14.

The call flow control table (Table III) may also include controlsequences for affecting a disconnect between the call completionequipment 10 and the telephone switching system 14. Such a disconnect isdesignated as control code C4. This disconnect code is utilized in thecontrol sequence to allow the call completion equipment 10 to disconnectthe communication line 22 extended to the telephone switching system 14,and recognize a new call from the calling party to the telephoneswitching system 14. This feature facilitates communications by allowingthe calling party to complete multiple calls to the telephone switchingsystem 14 without going on on-hook each time. The two-digit C4 controlsequence functions to temporarily suspend outpulsing of the callcompletion equipment 10 while the telephone switching system 14connection is interrupted. After a sufficient disconnect time, the callcompletion equipment 10 initiates outpulsing to the telephone switchingsystem 14. Since the initiation of any outpulsing by the call completionequipment 10 implicitly seizes the telephone switching system 14, thereis no need to execute any reoriginate control sequence. In addition, theC4 control sequence permits the call completion equipment 10 toautomatically illuminate a message waiting lamp on the telephone set 16of the called party. This is accomplished by placing a subsequent callto the telephone switching system 14 to which the appropriate digitsequence to illuminate such a lamp is sent.

Various other control sequences may be utilized to facilitatecommunications between the call completion equipment 10 and thetelephone switching system 14. A C5 control sequence specifies theinsertion of an incoming trunk number into an outpulsed digit stream.This control sequence allows the call completion equipment 10 todistinguish each call in progress.

A C6 flash control code is effective to generate a hook flash on thesubscriber line 22 connecting the call completion equipment 10 and thetelephone switching system 14. The hook flash is a short on-hookcondition of the subscriber line 22, followed by an off-hook condition.The hook flash duration conforms to standard telephony practices.

The foregoing call sequences and control sequences, together with thepersonality and translation tables, provide an enhanced integrationbetween voice store and forward facilities 19 and telephonecommunication switching systems 14. Described below are a number ofexamples which illustrate the features and advantages of the invention.The enhancements provided by the present invention will be apparent whencompared to the prior art techniques, in which communications throughthe telephone switching system 14 with a voice store and forwardfacility 19 were accomplished in the following manner to be describedbelow. Avoiding the cumbersome steps described below was only possibleif a telephone switching system had special voice store and forwardintegration capabilities and also only if the voice store and forwardfacility 19 was specifically designed to operate with the telephoneswitching system manufacturer's specific protocol. Such protocol optioninvolves data transmission over RS-232 links and special programs withinthe voice store and forward facilities and the telephone switchingsystem facility to handle such data.

First, on detecting a busy, no answer or otherwise unavailable conditionof a called party, the call completion equipment 10 would route the callto the voice store and forward facility for depositing a voice messagetherewith. Next, the calling party would then be cut through to thevoice store and forward facility 19, whereupon an audio voice promptwould be supplied to the calling party to input another code to signifywhether it is desired to deposit or retrieve a voice message. Yet anadditional prompt would be provided by the voice store and forwardfacility 19 to request the calling party to input the voice mailboxnumber, e.g. the called party's telephone extension number. The voicemessaging facility prompt would also inform the calling party to appendthe voice message with the input of a digit to signal the end of themessage. Provisions may be made in the voice store and forward facility19 for prerecording a short phrase by the called party to provide avoice identification to the calling party. Lastly, and at the end of thedeposited voice message, the calling party must input a code to signifythe end of the voice message. As noted above, many times this end ofmessage code is not input by the calling party, as the normal telephoneprocedure is simply to hang up once the communication is completed.

The functional operation of the invention to be described belowillustrates the simplicity with which calling parties can depositmessages in the voice store and forward facility 19. According to theinvention, the calling party simply inputs an initial code, for example"*", to indicate the desire to deposit a voice message in the voicestore and forward facility 19 and this simplicity is available withvirtually all telephone switching systems and voice storage facilitiesthat use inband signalling for the control of the messaging process. Thecalling party is then presented with the called party's voiceidentification, if any, and thereafter simply speaks to deposit thenvoice message. All other signalling matters with the voice store andforward facility 19 are automatically handled by the call completionequipment 10. Moreover, all signalling is handled using conventionaltechniques and practices.

The following illustrates in a more detailed manner the steps forcarrying out the principles and concepts of the invention. Particularlythe steps illustrate call processing of the invention once the callingparty has been provided with a voice prompt by the call completionequipment 10 concerning the option of leaving a voice message with thevoice store and forward facility 19.

First, the processor 72 of the call completion equipment 10 executes aloop, waiting for a digit transmission from the calling party. Atime-out occurs if no digits are received, whereupon default is made tothe preprogrammed default which could be a voice mailbox within thevoice storage facility. On the receipt of digits input by the callingparty, such digits are decoded and stored in digital form in theprocessor 72. Assuming the calling party responds to the voice prompt toinput a symbol "*" to deposit a voice message in the voice store andforward facility 19, the digital representation of the "*" is stored.

A translation table is then consulted, which translation table wastagged as a result of the entries in the personality table referred toabove. Section 1 of the associated translation table is scanned todetermine whether or not a match exists between the "*" symbol and atable entry. Associated with the symbol "*" is a call sequence and anindex to a call flow control table, as noted in Table II. As notedabove, if not match is found between the digits, the processor 72 isdirected to a default subroutine which connects the calling party to thepreprogrammed default. On a digit match, the processor 72 proceeds inobtaining the call sequence associated with the digit match. In theexample, the call sequence found corresponds to call sequence 15 whichis effective to outpulse the telephone extension digits input by thecalling party as an output sequence identifying the voice mailbox of thecalled party. The index located in Table II, Section 3, associated withthe matched digits also specifies an index to a call flow control table.Call processing continues, wherein the call sequence and the index tothe selected call flow control table (Table III) are specified in TableII. In the example, the entry in the call flow control table might be asshown below. The call flow control sequence is decoded as follows:##STR1##

In carrying out a recall sequence and the code sequence according to thecall flow control table, the voice store and forward directory number"200" is initially outpulsed to the voice messaging facility 19. Afterwaiting for an answer, the "7" digit is outpulsed, after the digits"200". It will be recalled that the digits "200" were initially dialedby the calling party in an attempt to communicate with the called party.Also, the outpulsing of the dialed extension number occurs as aextension. After waiting for a disconnect, the call termination code "9"is outpulsed. As can be appreciated, the processing steps are carriedout so that the call flow control sequence and outpulsing of digits arearranged for securing the services of the voice messaging facility 19with minimal input from the calling party. The arranged digits are thenoutpulsed to the voice messaging facility 19 in the sequence and in thetimed manner to provide signalling exchanges for establishing acommunication path to the message facility and place it in a state fordepositing a message in the correct voice mailbox. From the foregoingexample, a calling party can deposit any voice message with the voicestore and forward facility 19 if the called party is busy or does notanswer.

Other provisions are made for allowing outside calling parties todeposit a voice message with the voice store and forward facility 19without regard to whether the called party is busy or available. In thiscase, a typical voice prompt would be provided by the call completionequipment 10 to the calling party. As a result, the calling party wouldinput the digits, for example, 7300; the "7" indicating a desire todeposit a voice message, and the digits "300" indicating the voicemailbox number of the desired party. On the successful match of digitsin the translation table (TABLE II), a call sequence 16 is producedtogether with a call flow control entry defined by: ##STR2##

This sequence is similar to the foregoing call flow control entry,except here there is no need to add the digit "7" to the extensionnumber as such digit was initially entered by the calling party. In thistype of call, a second translation table is required. If, for example,the "C102" entry were "C100" or "C101", the sequence "7300" wouldretranslate, match the entry for "7300", and would yield the same entryshown above. This would be repeated until the processor 74 of the callcompletion equipment 10 stops the repetition after a predeterminednumber of times. To avoid this, a second translation table is used.Thus, when "7300" matches the entry in translation Table 1, the resultyields a call to the voice store and forward facility directly followedby the call completion equipment sending the digits necessary forleaving a message for extension "300".

As an additional example in which the invention facilitatescommunications with voice store and forward facilities, it is assumedthat an outside calling party desires to retrieve a voice message fromvoice mailbox "300", without ringing the called party. In this event,the calling party is greeted with a voice prompt, whereupon the callingparty inputs the digit string "6300". The call completion equipment 10then consults a translation table for a match with "6300". The matchyields a call sequence 16 and a call flow control entry defined by thefollowing: ##STR3##

In this example, the digit "6" dialed by the calling party signifies adesire to retrieve a voice message from the voice store and forwardfacility 19. On retrieving voice messages, the facility 19 generallyrequires a security code from the caller to verify that the message canbe retrieved only by the proper persons. As an alternative to the use ofa second translation table, a special code can be required of thecalling party to leave or retrieve a voice message without calling thecalled party. In response to the code, the call completion equipment 10would then dial the digits "2000" to access the voice store and forwardfacility 19. The call completion 10 would allow the calling party tocomplete the dialing directly with the voice store and forward facility.

In those situations where only certain telephone sets 16 of thetelephone switching system 14 have associated voice mailboxes in thevoice store and forward facility 19, a separate personality andtranslation table is provided. The different personality and translationtables supply different busy/no-answer messages depending on whether theextensions are associated with voice mailboxes. For purposes of example,assume that an incoming trunk 20 is associated with a first personality,which personality is associated with a first translation table.

All telephone extensions 16 which do not have voice mailboxes aretranslated to respective call sequences within the noted first table.The first personality then specifies the appropriate messages, whichmessages do not refer to voice mailbox options. The voice mailboxinvocation number would normally not appear in this table, or it mighttranslate to a default. Telephone extensions 16 which are associatedwith voice mailboxes are matched in this translation table with a callsequence 15. Further processing changes personality tables andretranslates, with the change being made to a second personality table.For purposes of example, the second personality table would utilize thesecond translation table. All telephone extensions 16 which areassociated with voice mailboxes translate to call sequence 1 which sendsdigits to the telephone switching system 14. This call sequence islocated within the second table. The second personality table isstructured to specify messages which refer to the voice mailbox option.The voice mailbox invocation number appears in the second translationtable, with call sequence 15, and a call flow control may be similar tothat shown below: ##STR4##

Telephone extensions 16 which are not associated with voice mailboxesare matched in the second translation table with call sequence 15. Suchtelephone extensions are thus characterized by a new personality tableand a new retranslation, with a change being made back to thepersonality table. While it might seem inappropriate to providetelephone extension numbers which do not have voice mailbox numberslisted in the second translation table, such a structure is needed if,during the message which gives the calling party an option to leave avoice message, the calling party instead calls a second extension numberwhich does not have an associated voice mailbox. The personality tableis changed in order to provide, among other things, a busy message whichallows the calling party to deposit a voice message. If, during the busymessage, the calling party dials an extension number of a party withoutassociated voice mailbox options, then a match in the translation tableis required to proceed back to the original personality table which doesnot invite the calling party to leave a voice message in response to abusy condition of a new called party.

It is important to also note that when the "*" is dialed by the callingparty to leave a voice message, call sequence 15 is utilized to changeto a third personality table and retranslate according to a thirdtranslation table. In the third translation table, there is one entryfor which the "*" digit is matched and yields call sequence 16 whichforces a call to the voice messaging facility, and a second entry whichutilizes call sequence 15 to return calling parties to the firstpersonality. Alternatively, the translation table associated with thethird personality may force calling parties dialing digits other than"*" to a default number. Essentially, this process forces all calls backto the first personality table in which the busy/no-answer message doesnot refer to a voice message option.

The reason for going back to the first personality table in order to usethe "busy" message is that when the voice store and forward facility 19is called, and all of its input ports are busy, it would beinappropriate to prompt the calling party to leave a voice message. Ofcourse, in those situations where the voice store and forward facilityis equipped with sufficient ports so that calling parties are neverrejected, the use of the third translation table may not be required.

Where outside parties make multiple calls without going on-hook, and inwhich the inside callers disconnect, the second personality table couldeither transmit the same primary message as that of the firstpersonality table or the system could change the personality on recallto that which existed with regard to the first personality table. Inbrief summary, the first personality table and the first translationtable handle busy/no-answer sequences for telephone extensions withoutvoice mailbox options. The second personality table and associatedsecond translation table handle busy/no-answer sequences for telephoneextensions equipped with voice mailbox options. Moreover, the thirdtranslation table is utilized to ensure that an appropriate message isgiven to the calling parties when all the ports of the voice store andforward system are busy.

Provisions are made in accordance with the invention for accommodatingsituations in which the telephone extension numbers of the telephonesets 16 do not identically match the voice mailbox numbers of the voicestore and forward facility 19. When the voice mailbox numbers are notthe same as the extension numbers, a control sequence is provided whichspecifies a retranslation in connection with a second translation table.With this arrangement, the telephone extension number dialed by thecalling party is translated into the appropriate voice mailbox number.For exemplary purposes, assume an incoming trunk 20 has associated withit a first personality table which utilizes a first translation table,and a second translation table which produces the voice mailbox numbers.A call sequence 15 call flow control "add digits" field would appear asfollows: ##STR5##

In this example, the voice store and forward facility 19 has a directorynumber of 2000. After waiting for an answer, the voice mailbox number isoutpulsed by the call completion equipment 10 via a retranslation of thedialed digits according to the second translation table. After waitingfor a disconnect, the termination code is outpulsed. If the extensionnumber 9000 was originally dialed by the calling party, and the voicemailbox number is 5000, the second translation table would match 9000,yielding an entry having a call flow control which deletes four digitsand inserts the digits 5000. The particular call sequence entry would beimmaterial, as call sequence 15 is invoked when the "*" is dialed todeposit voice mail. In any event, the call completion equipment 10outpulses the following sequence:

200 (Wait for Answer)

5000 (Wait for Disconnect)

9 (end of message)

The invention also makes provisions for providing voice mailbox servicesto various telephone extensions 16, groups of which may be serviced bydifferent voice store and forward facilities. An example of thissituation may be where multiple telephone switching systems arenetworked together, and where each such switching system is associatedwith a different voice store and forward facility. According to theinvention, a control sequence is specified which retranslates on asecond translation table to derive the particular directory number ofthe selected voice store and forward facility. In this manner, thedialed number directly selects a desired voice store and forwardfacility. Assume again that an incoming trunk 20 originates in a firstpersonality table and a first translation table, and a secondtranslation table which produces the desired numbers of the voice storeand forward facilities.

A sample call sequence 15 having a call flow control "add digits" fieldwould appear as C12C2C100C39. In this case, the directory number of thevoice store and forward facility is selected by a retranslation on asecond translation table. After waiting for an answer, the dialed digitsare outpulsed via the retranslation on the same translation table usedwhen calling the extension. After waiting for a disconnect, thetermination code is outpulsed by the call completion equipment 10. If acalling party dialed the number 9000 to deposit a voice message with avoice store and forward facility identified by directory number 3000, aretranslation on a second table would match 9000, yielding an entry witha call flow control which would delete four digits and insert the digits3000. The call completion equipment would outpulse the following digitstring:

3000 (Wait for Answer)

9000 (Wait for Disconnect)

9 (end of message).

It is a conventional practice to illuminate a lamp on a telephone set 16whose associated voice mailbox has a message deposited therein. The callcompletion equipment 10 of the invention is adapted to transmit signalsto the telephone switching system 14 when such telephone switchingsystem supports such a capability to cause appropriate telephone setlamps 17 to be illuminated after the deposit of voice messages with thevoice store and forward facility 19. In this situation, a controlsequence processed by the processor 72 causes a disconnect between thecall completion equipment 10 and the telephone switching system 14, andthen a subsequent reconnect to place a second internal call toilluminate the telephone set lamp 17. Of course, the telephone switchingsystem 14 would be of the type which responds to special dialing codesto illuminate selected telephone set lamps 17.

As an example, assume an incoming trunk 20 originates in a firstpersonality table and a first translation table. A call sequence 15 callflow control "add digits" field would appear as follows: ##STR6##

In this example, the directory number of the voice store and forwardsystem is "9000". After two pauses, the digits dialed by the callingparty are outpulsed via a retranslation on the translation tableutilized when calling the extension (C100). After waiting for adisconnect, code (C3), a termination code "9" is outpulsed. The callcompletion equipment 10 next idles the telephone switching system 14 bya disconnect code (C4), and waits for a specified guard time accordingto standard telephone system practices. The call completion equipment 10then reseizes the telephone switching system 14 and waits untiloutpulsing can begin. The access code for turning on a message waitinglamp in the example is 60. The dialed digits are again outpulsed via aretranslation on the same translation table utilized when calling theextension (C100). A pause (F) allows time for the telephone switchingsystem 14 to answer and deliver a confirmation tone. Finally, thetelephone switching system 14 is again idled by the execution of thecode (C4).

According to another feature of the invention, the call completionequipment 10 can provide a default to the voice store and forwardfacility 19. Such a default can be utilized when the telephone set 16 ofthe called party is busy, whereupon the call completion equipment 10automatically invokes the voice store and forward option to assist thecalling party in completing a call. When a single voice store andforward facility is utilized, and when each voice mailbox numbercorresponds to the telephone extension number, and the message waitinglamp is not utilized, one personality and translation table issufficient to carry out the default function. Assume that the maindefault index of the personality is "1", then the digit "0" will beoutpulsed and route the calling party to the switchboard attendant 18when no digits are dialed according to the primary message prompt. If nodigits are dialed during the busy or no-answer message, the busy andno-answer default table indices will both be set to "2". The defaulttable entry "2" would appear as follows: 2000 C 2 C100 C 39.

In this example, the directory number of the voice store and forwardfacility is 2000. After waiting for an answer, the dialed digits areoutpulsed via a retranslation on the same translation table utilizedwhen the call was made to the respective extension telephone. As aresult, the calling party dialing no digits will be connected to thecalled party's voice mailbox. After waiting for a disconnect, atermination code is outpulsed to the voice store and forward system 19.

The Appendix illustrates the various entries in the personality tables,the translation tables and the call flow control tables according to thepreferred embodiment of the invention. In particular, Table IVillustrates personality table entries, Table V illustrates translationtable entries and Table VI indicates call flow control table entries.The incoming trunks 20 to the call completion equipment 10 originate ina single customer group which start with a first personality.Personality "1" will handle the telephone extension denied voice mailboxoptions, while personality "2" handles the telephone extensions allowedvoice mailbox options. Some of these parameters appear in the appendixin connection with Table IV. The usage and contents of exemplarytranslation tables are illustrated below in Table V. Call flow controlentries of a number of call flow control tables are illustrated in TableVI. Two default entry tables are shown in connection with Table VII.

From the foregoing, disclosed is call completion equipment forfacilitating the cooperation between calling parties and voice store andforward equipment. The call completion equipment operates in conjunctionwith the telephone switching system to provide voice prompts to callingparties to assist in expediting calls to telephone sets serviced by theswitching system, as well as operates to connect calling parties tovoice store and forward facilities in the event that called parties areunavailable. The call completion equipment provides a voice prompt tocalling parties to input telephone extension numbers to complete callsto the called parties. In the event of a busy or no-answer condition ofthe called party, or if message leaving or retrieving is initiallyselected by the calling party, the telephone extension number isoutpulsed, together with other digit information, to the voice store andforward facility for automatic connection with the voice mailbox of thecalled party. The connection of the voice store and forward facility tothe calling party by the call completion equipment is transparent to thecalling party and to the telephone switching system, therebyfacilitating the utilization of the voice store and forward functionswith the calling parties. The call completion equipment is provided witha number of personality tables, translation tables and call flow controltables to provide communications and inband signalling transmissions tothe voice store and forward facility for providing an automaticconnection thereto. The voice messaging facility is also automaticallyplaced in a state for receiving and storing a voice message, or for theretrieval of a previously deposited message. By the use of the varioustables, the call completion equipment can outpulse information to placethe voice messaging facility in a state for retrieving or depositing avoice message from the calling party, or translate telephone extensiondigit information into other information representative of a voicemailbox number associated with the called party. Also, by the programmedutilization of the various tables, an enhanced flexibility of the callcompletion equipment is provided such that a large variety of situationscan be accommodated for connecting calling parties with the voice storeand forward facility. In addition, enhanced performance is provided inthe call completion equipment for transmitting disconnect information tothe voice store and forward facility for reducing the overall portactive time of such facility.

While the preferred embodiment of the invention has been disclosed withreference to a specific call completion apparatus, it is to beunderstood that many changes in detail may be made as a matter ofengineering choices without departing from the spirit and scope of theinvention as defined by the appended claims.

APPENDIX

                  TABLE I                                                         ______________________________________                                        Personality Table                                                             ______________________________________                                        Translation Table                                                                              There are preferably 8 to 32                                                  different tables by which                                                     dialed numbers can be                                                         interpreted.                                                 Number of Recalls                                                                              If the inside party hangs up                                                  first the outside party may                                                   make a recall.                                               Recall Personality                                                                             The Personality to use on a                                                   recall.                                                      Mode             Answer immediately, delay                                                     answer, transfer mode, direct                                                 mode.                                                        Answer Delay     Define how much time the Call                                                 Completion Equipment (CCE)                                                    allows the live operator to                                                   answer before the CCE                                                         answers.                                                     Message Numbers for the                                                                        Identifies the message to be                                 Main Message     played on new, incoming                                                       calls.                                                       Dialing Timeout  Dialing time allowed after                                                    main message completion                                                       before the call defaults.                                    Default Telephone Numbers                                                                      Operator or station to which                                 (Main, Busy, No-answer)                                                                        calls needing assistance will                                                 be sent.                                                     Busy, No-answer Messages                                                                       Defines the messages to play                                                  in these cases.                                              Camp-on (hold) Retries                                                                         Defines the number of times a                                Allowed          busy extension will be                                                        retried before giving the                                                     call a message.                                              Type of Music on Hold                                                                          (Music provided for: all                                                      calls, camp-on calls only,                                                    etc.)                                                        ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        Translation Table                                                             ______________________________________                                        SECTION 1                                                                     DIGITS                                                                        Digits to be matched, such as                                                 extension numbers, codes such as                                              dialing to hold, security codes,                                              codes to invoke another message, etc.                                         ______________________________________                                        SECTION 2                                                                     CS      DESCRIPTION                                                           ______________________________________                                        1       Send dialed digits with or without modifying.                         2       Send dialed digits with or without modifying,                                 only if valid security code has been received.                        3       Send caller to active main default location.                          4       This is a valid security code.                                        5       Send caller to busy tone, then, disconnect.                           6       Route caller to another message.                                      7       Cut caller through to PBX.                                            8       Overlap outpulsing.                                                   9       This is a camp-on code.                                               10      Send caller to active do not answer default                                   location.                                                             11      Send caller to active busy default location.                          12      This is a ringback learn code.                                        13      This is a busy learn code.                                            14      Change to alternate Personality, discard digits,                              and play new main message.                                            15      Change to alternate Personality and retranslate                               received digits.                                                      16      Redirect previously matched digits.                                   17      Change to alternate Personality, retain digits,                               and play new main message.                                            18      Print SMDR record, change to alternate                                        Personality, and play new main message.                               19      Save digits as security code, change to                                       alternate Personality, and play new main                                      message.                                                              21      Activate new Personality for Customer Group 1.                        22      Activate new Personality for Customer Group 2.                        23      Activate new Personality for Customer Group 3.                        24      Activate new Personality for Customer Group 4.                        40      Start DTMF receiver test.                                             ______________________________________                                        SECTION 3                                                                     INDEXES                                                                       Indexes to call flow control                                                  table, can be 0-32 indexing the                                               entries thereof.                                                              ______________________________________                                    

                  TABLE III                                                       ______________________________________                                        Call Flow Control Table                                                       INDEX   CODES                                                                 (1-32)  AND/OR DIGITS FUNCTION                                                ______________________________________                                        1       CO            Change mode from tone to                                                      rotary dial.                                            2       ClXX          Retranslate dialed digits,                                                    send to PBX.                                            3       C2            Wait for PBX Answer.                                    4       C3            Wait for CO or PBX answer.                              5       C4            Disconnect from PBX.                                    6       C5            Insert Trunk Number.                                    7       C6            Hook flash.                                             8       200C0300      Send 200 in DTMF, Send                                  .                     300 in rotary pulse.                                    .                                                                             32                                                                            ______________________________________                                    

                  TABLE IV                                                        ______________________________________                                        Personality Table                                                                              Personality 1                                                                          Personality 2                                       ______________________________________                                        TTN    Translation Table                                                                             1          2                                           MlMN   Main Message Number                                                                           1          1                                           MDN    Main Default Index                                                                            1          1                                           DNMN   No-answer Message                                                                             16         28                                          DNDN   No-answer Default                                                                             1          2                                           BMN    Busy Message Number                                                                           17         29                                          BDN    Busy Default Index                                                                            0          0                                           ______________________________________                                    

                  TABLE V                                                         ______________________________________                                        Translation Table                                                             TABLE NUMBER            CALL    Call Flow Con-                                & USAGE        DIGITS   SEQ     trol Table Index                              ______________________________________                                        1   Extensions which do                                                                          0        3     0                                               not have mailboxes                                                                           8        9     0                                                              9        1     0                                                              31FF     15    2                                                              3FFF     1     0                                                              42FF     15    2                                                              4FFF     1     1                                                              FFFF     3     0                                           2   Extensions which do                                                                          0        15    1                                               have voice mailboxes                                                                         5        16    0                                                              8        9     0                                                              9        15    1                                                              31FF     1     0                                                              42FF     1     1                                                              FFFF     15    1                                           3   Voice mail machine                                                                           31FF     1     1                                               directory numbers                                                                            42FF     1     2                                           4   Mailbox numbers                                                                              31FF     1     1                                                              42FF     1     2                                           5   Waiting lamp numbers                                                                         FFFF     1     1                                           ______________________________________                                    

                  TABLE VI                                                        ______________________________________                                        Call Flow Control Table                                                                      ENTRY                                                          TABLE NUMBER   NUM-     # TO      ADDED                                       & USAGE        BERS     DELETE    DIGITS                                      ______________________________________                                        1   Extensions which do                                                                          1        0       88F                                           not have mailboxes                                                        2   Extensions which do                                                                          1        0       88F                                           have voice mailboxes                                                                         2        0       C103C2                                                                        #C104C3                                                                       *C428C105C4                               3   Voice mail machine                                                                           1        4       133                                           directory numbers                                                                            2        4       88F134                                    4   Mailbox numbers                                                                              1        2       50                                                           2        2       51                                        5   Waiting lamp numbers                                                                         1        1       None                                      ______________________________________                                    

                  TABLE VII                                                       ______________________________________                                        Default Table                                                                 ENTRY NUMBER    CONTENTS                                                      ______________________________________                                        1               0                                                             2               C103C2#C104C3*C428C105C4                                      ______________________________________                                    

What is claimed is:
 1. A method of facilitating the integration of avoice store and forward function with telephone switching apparatus,comprising the steps of:using a call completion system remote from acalling party to prompt the calling party to enter firstdestination-determining information relating to a called party;receiving said first destination-determining information; determiningthat a called party to whom the calling party wishes to communicate isunavailable; transmitting a signal to the calling party indicating theunavailability of the called party; collecting seconddestination-determining information from the calling party forconnecting the calling party to a voice store and forward facility;initially isolating the calling party from the voice store and forwardfacility so that the calling party cannot hear audible prompts which maybe generated by the voice store and forward facility; translating saidfirst and second destination-determining information into a first codeidentifying a voice store and forward facility, and a second codeidentifying a voice mailbox associated with the called party; causingthe switching apparatus to access said voice store and forward facilityand for causing said switching apparatus to establish a communicationpath to the facility; transmitting said first and second code to saidfacility via said communication path; and connecting said calling partyto said communication path so that said calling party can deposit avoice message with said voice store and forward facility.
 2. The methodof claim 1, and further including the step of connecting the callingparty to said communication path in such time as to allow the callingparty to receive a second voice prompt generated by the voice store andforward facility.
 3. The method of claim 1, and further including thesteps of monitoring the connection status of the calling party,detecting a disconnect, and transmitting an indication thereof to thevoice store and forward facility for termination of service therewith.4. A method of facilitating the integration of a voice store and forwardfunction with telephone switching apparatus, comprising the stepsof:using a call completion system remote from a calling party to promptthe calling party to enter first destination-determining informationrelating to a called party; receiving said first destination-determininginformation; determining that a called party to whom the calling partywishes to communicate is unavailable; transmitting a signal to thecalling party indicating the unavailability of the called party;collecting second destination-determining information from the callingparty for collecting the calling party to a voice store and forwardfacility; maintaining a library of all called parties serviced by thetelephone switching apparatus whether or not voice store and forwardfunctions are available thereto; preventing the calling party from usingthe voice store and forward facilities when the library shows that thevoice store and forward facility is not available to the called party;initially isolating the calling party from the voice store and forwardfacility so that the calling party cannot hear audible prompts which maybe generated by the voice store and forward facility; translating saidfirst and second destination-determining information into a first codeidentifying a voice store and forward facility, and a second codeidentifying a voice mailbox associated with the called party; causingthe switching apparatus to access said voice store and forward facilityand for causing said switching apparatus to establish a communicationpath to the facility; transmitting said first and second code to saidfacility via said communication path; and connecting said calling partyto said communication path so that said calling party can deposit avoice message with said voice store and forward facility.
 5. The methodof claim 1, and wherein said second code comprises a telephone extensionnumber of the called party.
 6. The method of claim 1, and furtherincluding translating said first destination determining informationinto other information to thereby translate an extension number intoanother number defining a voice mailbox number residing in said voicestore and forward facility.
 7. A method of facilitating the integrationof a voice store and forward function with telephone switchingapparatus, comprising the steps of:using a call completion system remotefrom a calling party to prompt the calling party to enter firstdestination-determining information relating to a called party;receiving said first destination-determining information; determiningthat a called party to whom the calling party wishes to communicate isunavailable; transmitting a signal to the calling party indicating theunavailability of the called party; collecting seconddestination-determining information from the calling party forconnecting the calling party to a voice store and forward facility;initially isolating the calling party from the voice store and forwardfacility so that the calling party cannot hear audible prompts which maybe generated by the voice store and forward facility; translating saidfirst and second destination-determining information into a first codeidentifying a voice store and forward facility, and a second codeidentifying a voice mailbox associated with the called party; causingthe switching apparatus to access said voice store and forward facilityand for causing said switching apparatus to establish a communicationpath to the facility; transmitting said first and second code to saidfacility via said communication path; connection said calling party tosaid communication path so that said calling party can deposit a voicemessage with said voice store and forward facility; and transmittinginformation to the switching apparatus for illuminating a message lampassociated with the called party, said transmission being transparent tothe voice store and forward facility.
 8. A method of facilitating theintegration of a voice store and forward facility with telephoneswitching apparatus, comprising the steps of:responding to a request forservice directed to the telephone switching apparatus; prompting acalling party originating the request for service as to the manner forcompleting a call to the switching apparatus; in response to said stepof prompting, collecting first destination-determining information fromthe calling party, storing said first destination-determininginformation and transmitting the first destination-determininginformation to the telephone switching apparatus to complete a call to acalled party associated with the first destination-determininginformation and said switching apparatus; detecting an unavailabilitycondition of the called party; prompting the calling party to select oneof a plurality of options including an option of invoking the service ofthe voice store and forward facility; receiving second information fromthe calling party concerning a request to be connected to the voicestore and forward facility; using the first destination-determininginformation and the second information in generating a signal differentfrom the first destination-determining information; signalling the voicestore and forward facility with said signal that a voice message is tobe deposited therewith; signalling the voice store and forward facilityof the identity of a voice mailbox with which said voice message is tobe deposited; and causing a connection to be made between said voicestore and forward facility and the calling party.
 9. The method of claim8, wherein said step of generating the signal comprises processing thefirst destination-determining information and the second informationinto a digit sequence; andtransferring the digit sequence through theswitching apparatus to the voice store and forward facility to invokethe services thereof.
 10. The method of claim 9, and further includingthe steps of:storing a plurality of different predetermined callsequences; retrieving a stored call sequence based on parametersincluding the first destination-determining information; using theretrieved call sequence to cause a connection to be established throughthe switching apparatus between the calling party and the voice storeand forward facility; and thereafter transmitting on said connection thedigit sequence.
 11. The method of claim 8, and further including thestep of generating said signal in call completion apparatus remote fromthe calling party.
 12. A method of facilitating the integration of avoice store and forward function, comprising the steps of:associatingeach of a number of incoming trunks to a call completion equipment withan entry of a personality table having a plurality of entries, eachentry defining characteristics to be ascribed to calls on trunksassociated therewith; associating with each entry in the personalitytable a translation table, each translation table having a digitmatching section, a call sequence section, and a section of call flowcontrol table indices; associating a call flow control table with eachcall flow control table index of said translation table; receiving froma calling party on one said trunk an indication to be connected to avoice store and forward facility; determining a personality of said onetrunk according to a corresponding entry in the personality table;accessing a predefined one of the translation tables according to thelast said personality table entry; determining a call sequence accordingto the translation table; accessing a predefined one of the call flowcontrol tables according to an index of the accessed translation table;defining a digit string to be output according to the accessed call flowcontrol table; and transmitting the digit string to the voice store andforward facility for invoking the services thereof.
 13. The method ofclaim 12, and further including searching through a digit matchingsection of said accessed translation table to determine whether a calledparty has a voice mailbox associated with said facility.
 14. A method offacilitating the integration of a voice store and forward function,comprising the steps of:associating each of a number of incoming trunksto a call completion equipment with an entry of a personality tablehaving a plurality of entries, each entry defining characteristics to beascribed to calls on trunks associated therewith; associating with eachentry in the personality table a translation table, each translationtable having a digit matching section, a call sequence section, and asection of call flow control table indices; associating a call flowcontrol table with each call flow control table index of saidtranslation table; receiving from a calling party on one said trunk anindication to be connected to a voice store and forward facility;determining a personality of said one trunk according to a correspondingentry in the personality table; accessing a predefined one of thetranslation tables according to the last said personality table entry;determining a call sequence according to the translation table;accessing a predefined one of the call flow control tables according toan index of the accessed translation table; defining a digit string tobe output according to the accessed call flow control table;transmitting the digit string to the voice store and forward facilityfor invoking the services thereof; searching through a digit matchingsection of said accessed translation table to determine whether a calledparty has a voice mailbox associated with said facility; transmitting tothe calling party an audible prompt indicating a voice message facilityif a match in aid digit matching section is found; and preventing saidstep of transmitting if no match is found.
 15. The method of claim 12,and further including modifying digits input by the calling party usingsaid accessed call flow control table, and outpulsing said modifieddigits as a voice mailbox number to said facility.
 16. The method ofclaim 12, and further including forming from said call flow controltable a digit string having a directory number identifying saidfacility, at least one digit for identifying whether a voice message isto be deposited or retrieved, and a number of digits identifying a voicemailbox of said facility.
 17. The method of claim 16, and furtherincluding forming in said digit string a pause for allowing processingtime by said facility.
 18. Call completion equipment for interfacing avoice store and forward facility with a telephone switching system,comprising:means for receiving and storing destination-determininginformation entered by a calling party from a telephone remote from saidcall completion equipment, said information intended for completing acall to a called party associated with the telephone switching system;means in said call completion equipment responsive to a predetermineddialed code from the calling party indicating a desire to communicatewith the voice store and forward equipment for transmitting to thetelephone switching system a number for accessing said voice store andforward facility; and means in said call completion equipment fortransmitting to said telephone switching system facility identifyinginformation based on said destination-determining information forproviding access to a voice mailbox of the voice store and forwardfacility; and further including means transparent to the voice messagefacility for controlling a connection between the calling party and thevoice message facility so that the switching system can be accessedafter the calling party has completed his message to illuminate amessage lamp associated with a called party.
 19. Call completionequipment for interfacing a voice store and forward facility with atelephone switching system, comprising:means for receiving and storingdestination-determining information entered by a calling party from atelephone remote from said call completion equipment, said informationintended for completing a call to a called party associated with thetelephone switching system; means in said call completion systemequipment responsive to a predetermined dialed code from the callingparty indicating a desire to communicate with the voice store andforward equipment for transmitting to the telephone switching system anumber for accessing said voice store and forward facility; means insaid call completion equipment for transmitting to said telephoneswitching system facility identifying information based on saiddestination-determining information for providing access to a voicemailbox of the voice store and forward facility; and further includingmeans for adding digits to the facility identifying informationindicating that access to the voice store and forward equipment is fordepositing a voice message.
 20. Call completion equipment forinterfacing a voice store and forward facility with a telephoneswitching system, comprising:means for receiving and storingdestination-determining information entered by a calling party from atelephone remote from said call completion equipment, said informationintended for completing a call to a called party associated with thetelephone switching system; means in said call completion equipmentresponsive to a predetermined dialed code from the calling partyindicating a desire to communicate with the voice store and forwardequipment for transmitting to the telephone switching system a numberfor accessing said voice store and forward facility; means in said callcompletion equipment for transmitting to said telephone switching systemfacility identifying information based on said destination-determininginformation for providing access to a voice mailbox of the voice storeand forward facility; and further including means for suppressingselected voice prompts generating by the voice store and forwardfacility from reaching the calling party.
 21. A method for usingautomated apparatus in integrating a voice store and forward facilitywith a telephone switching system, comprising the steps of:sensing anincoming call on a trunk coupled to the telephone switching system;prompting a caller who made the call to enter firstdestination-determining information associated with at least one calledparty; receiving and storing the first destination-determininginformation; determining that the called party is unavailable; storing atranslation table having as first entries a plurality of pieces ofdestination-determining information and as second entries correspondingto the first entries indications as to whether a voice store and forwardoption is available for corresponding first entries; referring to thetable to determine whether a voice store and forward option exists forthe received destination-determining information; transmitting a secondprompt to the caller advising him of a plurality of options including avoice store and forward option in response to determining that a voicestore and forward option exists for the received destination-determininginformation; and transmitting a third prompt to the caller advising himof a plurality of options not including a voice store and forward optionin response to determining that a voice store and forward option doesnot exist for the received destination-determining information. 22.Automated apparatus for integrating a voice store and forward facilitywith a telephone switching system having a plurality of trunks coupledthereto, comprising:a detector for sensing an incoming call on one ofsaid trunks; a receiver for receiving destination-determininginformation from a caller making said incoming call, at least one calledparty associated with said destination-determining information; meansfor storing said received destination-determining information; means fordetermining that the called party is unavailable; means for storing aplurality of predetermined call sequences, at least some of said callsequences determining whether a connection to said voice store andforward facility is to be made; a processor for assigning one of saidplurality of call sequences to said call, in response to theunavailability of the called party and as a function of said receiveddestination-determining information; and means controlled by saidprocessor for completing the call to a destination as controlled by saidassigned call sequence and further comprising means for detecting thecompletion by the caller of a message left at the voice messagefacility; means separate from said voice store and forward facility foraccessing said telephone switching system in response to said means fordetecting the completion by the caller, said means for accessingcontrolled by said processor to illuminate a message lamp associatedwith a called party without involving said voice store and forwardfacility.
 23. Automated apparatus for integrating a voice store andforward facility with a telephone switching system, comprising:at leastone trunk coupled to a telephone switching system; a detector forsensing an incoming call on said trunk; a prompter for prompting acaller who made said call to enter destination-determining informationassociated with at least one called party; a receiver for receiving saiddestination-determining information; means for storing said receiveddestination-determining information; means for determining that thecalled party is unavailable; means for storing a translation tablehaving as first entries a plurality of pieces of destination-determininginformation and as second entries corresponding to said first entriesindications as to whether a voice store and forward option is availablefor respective ones of the first entries; a processor for referring tosaid table to determine whether a voice store and forward option existsfor said received destination-determining information; said promptercontrolled by said processor for transmitting to said caller a secondprompt advising him of a plurality of options including a voice storeand forward option in response to said processor determining that avoice store and forward option exists for said receiveddestination-determining information, said prompter controlled by saidprocessor for transmitting a third prompt to said caller advising him ofa plurality of options not including a voice store and forward option inresponse to said processor determining that a voice store and forwardoption does not exist for said received destination-determininginformation.
 24. Apparatus for automatically accessing a voice store andforward facility in the event that an outside caller is unable tocommunicate with a called party accessible through a telephone switchingsystem, comprising:a receiver for receiving called partydestination-determining information; means for sensing that said calledparty is unavailable; means responsive to said means for sensing fortransmitting a message to the calling party to indicate theunavailability of the called party; means for receiving from the callingparty an indication that the calling party desires to leave a messagefor the called party; a processor coupled to said receiver and saidmeans for receiving for generating a call flow control code as afunction of said indication and said called partydestination-determining information, said call flow control codeoperable to control the timing and manner in which said voice store andforward facility will be accessed; means controlled by said processorfor leaving a message in the voice store and forward facility accordingto the timing and manner established by the call flow control code; andfurther comprising means for storing a plurality of voice store andforward telephone numbers; means for retrieving one of said voice storeand forward telephone numbers as a function of said called partydestination-determining information; and means for incorporating saidretrieved voice store and forward telephone number into said call flowcontrol code.